One million fewer passengers passed through BAA's seven airports last month compared with November last year, as the economy worsened and services were hit by protests in Bangkok and a strike at Air France.

The company, which owns seven airports including Heathrow, Gatwick, Stansted, and Edinburgh, said the volume of passengers in November dropped by 8.9% compared with the same month last year. This year, total traffic is down 2.4%.

Owned by the Spanish construction firm Ferrovial, BAA said the "underlying trend had worsened" with the start of the reduced winter schedule of flights. But it also blamed the disruptions in Thailand and France. Bangkok airport was brought to a standstill by anti-government protesters for eight days.

BAA said 9.8 million people travelled through its airports in November, down from 10.8 million. This year, the airports have handled 134.6 million passengers. The figures will provide ammunition to opponents of expansion of Heathrow and Stansted. But BAA said it remained confident passengers would return.

Heathrow proved the most resilient of the BAA airports, with traffic down 4.8% on the same month last year, partly because the open skies agreement meant there were additional US services. Gatwick, which is up for sale, was down 13.5% and Stansted was down 13.2%. There was a 15.6% decline at Glasgow, an 11.5% drop at Aberdeen and 7.8% at Edinburgh. BAA's other airport, Southampton, was down 9.7%.